Hi VWM,
i don't know whether you understand what i meant.
I will do my best and try to explain it better.
It goes not around in regarding no deposit bonusse, the problem is that accounts from some european players are closed because they get reproached played in deceitful intention.
And it always will happen if the players try to make a cash out.
What CC do is, that none of them will say what's the exactly reason for it.
Nobody will do it and that's not fair and a shame for an "accredited casino".
I do understand, however you are saying that there is a pattern that seems based on location, rather than the player's own actions, that seems to contribute to the problem.
Casinos tend to view entire countries as "deceitful players", and whereas some players will be given the benefit of the doubt, the SAME actions from a player who resides in a "deceitful country" will result in confiscated winnings and a "F*&^% off" from the casino.
This seems to be affecting players from Europe disproportionately, so they must be doing "something wrong", yet they probably obey all the rules.
Some while ago, it was revealed that casinos track the "quality" of players they receive through different routes. In Denmark, an advantage strategy was posted on a big public forum, not itself an affiliate, but casinos got to know about it as they saw a flood of players playing by rote from instructions they saw on this forum. THIS may well be the explanation, nothing to do with broken rules, but more down to many players following by rote a very specific sequence of plays, which collectively gives a +EV result, even if the rate of winners is itself under 50%. These strategies are usually "win or bust", and when accounts of winners are audited they seem to play almost the EXACT sequence of bets, and cash out at the same point in this sequence. The casino will then, in hindsight, define this sequence as "bonus abuse", and start voiding winnings.
The players involved are NOT "cheats", or "frauds", they have just taken advantage of "an education". Players who have NOT EVER seen this rote method published, but are skilled enough to work it out themselves, will ALSO get their winnings confiscated, and it is THEY who are going WTF
To find out what is going on, just ask a few of these players what they did, game by game, and deposit and withdrawal history. You will probably see a striking similarity between their actions. If so, ask them how they found the strategy, on the internet (which forum/site), or did they work it out for themselves.
I suspect it most likely involves the "double up & grind" strategy, of which there are many variants, some blindingly obvious, some less so - but all are overall +EV.